One of the world’s most endangered animals used to be routinely seen off the NC coast. Not anymore.
WILMINGTON — After years of steady improvement, one of the Atlantic ocean’s most at-risk whales — a species with strong ties to North Carolina — is in perilous decline, according to researchers.
The North Atlantic right whale, historically a target for harpooners, saw its population improve from 270 whales in 1990 to 483 in 2010, according to research led by Richard Pace of the National Oceanic and Atmospheric Administration (NOAA)’s Northeast Fisheries Science Center, based in Woods Hole, Massachusetts. The population fell to 458 whales by 2015.
“When you’re talking about a population that’s somewhere between 400 and 500 individuals, you can never let your guard down. And you can never assume that things are going well,” said Ann Pabst, a University of North Carolina Wilmington (UNCW) zoologist whose lab focuses on marine mammals.
The downward trend continued in 2017, with 16 North American right whales dying, putting the species’ population in decline and at risk of endangerment. The Pace team’s research indicates the female population declined about 7 percent from 2010 to 2015, while the male population dropped about 4 percent.
“Females have a lot riskier life. They spend a lot more time up and down the coast, they migrate a lot more to give birth,” McLellan said. “Males generally stay north. … They’re sitting in one location, and they’re not exposing themselves to the mortality factors.”
Threats to whales include entanglement in fishing gear, a trend that some research indicates is increasing. Whales that are caught in fishing gear often exhaust themselves trying to escape, resulting in long term impacts even when they manage to get out.
The mammals are also susceptible to ship strikes, and changing migration patterns could be putting them at more risk.
“They’re now significantly back in the crosshairs of the potential to go extinct,” McLellan said, adding, “We have 70 (adult) females that are going to reproduce the recovery of a species.”
Where are right whales found?
Another recently published study also led by NOAA scientists has implications for whale sightings off the North Carolina coast. Using bottom-mounted acoustic monitoring, the study determined whales have spent less time in the mid-Atlantic region since 2010, while also being found less often off of the Gulf of Maine.
Published in the Nature Scientific Reports journal, the research used data collected from 35,600 days and 324 listening devices, with information spanning a period from 2004 to 2014.
Previously, North Atlantic right whales were believed to mostly live in waters off Florida and Georgia in the winter months, moving to feeding grounds off New England and Canada during the summer. The acoustic research confirmed those patterns, but also indicated that some whales don’t migrate.
“It isn’t clear what it causing changes in right whale occupancy since 2010,” Genevieve Davis, an acoustician at NOAA’s Northeast Fisheries Science Center’s Woods Hole Laboratory, said in a release. “It could be a response to human causes or to the changing environment, or both.”
Changing migratory patterns could impact the species’ chances of survival, as rules structured to protect the species are less effective. For instance, there are limits on ship speed in the waters where researchers expect the endangered species to be found, a measure meant to prevent fatal ship strikes.
If the whales are in unexpected waters where the measures have not been implemented, a fatal strike becomes more likely.
“Right now,” Pabst said, “right whales are not necessarily paying attention to our understanding of where they’re supposed to be and when they’re supposed to be there.”
This summer, 10 of the 13 whale carcasses found were in the Gulf of St. Lawrence, north of the whales’ expected range. Canada acted quickly, trying to remove fishing gear from the water by closing the nation’s snow crab fishery and asking boaters to reduce speeds in the area.
Whales found in unexpected places — McLellan and Pabst both suggested they’re chasing food — have forced scientists to consider a new approach to the animals’ protection.
“The scientific community,” McLellan said, ’is saying, ‘Do we wait until we prove these distributions? Or do we just say where there are right whales, we need to add more specific management plans?’”
Right whales are also, the research indicated, less likely to be found off Cape Hatteras in the summer and fall than they were before 2010. It is common, McLellan said, for the first right whale sighting of the season in the Southeast to happen off the coast of Wrightsville Beach.
“This is an animal that routinely visits the water off North Carolina,” Pabst said. “It is a species that can be found in North Carolina almost any month of the year, and at least one extremely famous white whale, Calvin, has at least twice had her calf in the waters off North Carolina.”
Still, there have been no sightings yet this year. And the number of whales in the calving grounds — where whales raise their young — off the coast of Florida and Georgia has fallen from a high of 225 known whales in the recent past to 11 last winter.
“The number of animals moving south anymore is just not here,” McLellan said. “The animals are prospecting in other areas, they’re trying to find food.”
Reporter Adam Wagner can be reached at 910-343-2389 or Adam.Wagner@GateHouseMedia.co